What is the meaning for assalamu alaikum?

According to the Islamic Dictionary, it literally means: "Peace be upon you." It is a shortened form of a phrase that translates to "Peace be unto you and so may the mercy of Allah and His blessings."

There were no fist bumps, but there were many interesting moments during Obama's speech in Cairo. The moment that got the most attention, in Search anyway, was Obama's use of "assalamu alaikum." Said the President: "I'm also proud to carry with me the goodwill of the American people, and a greeting of peace from Muslim communities in my country: Assalaamu alaykum."

The President quoted from the Holy Koran several times, including this key quote that drew big applause: "The Holy Koran teaches that whoever kills an innocent, it is as if he has killed all mankind; and whoever saves a person, it is as if he has saved all mankind."